Low-water alarm.



No. 678,735. Patented July I6, |90I.

C. B. HODGES.

Low WATER ALARM.

(Application led Sept. 19, 1900.) (No Model.)

Miren @raras Parent Cierres,

CLARENCE B. HODGES, OF DETROIT, MICHIGAN.

LOW/WATER ALARM..

lE53?EGIEIGA'LEIGN forming part of Letters Patent No. 678,735, dated July 16, 19.01 Application filed September 19, 1900. Serial No. 80.473. (No model.)

and has for its object improvements in that class of alarms in which a signal is sounded by the automatic opening of a valve and admission of steam to the signal whenever the water in the boiler reaches a predetermined depth. Y

In tbe drawings, Figure l shows the alarm in elevation, parts being sectioned. Fig. 2 is a detail of an air-outlet valve at the top o f the structure.

A indicates a standspipe screwed into a coupling B, of which the lower end is screwed into an elbow C. The elbow C is adapted to be and is intended to be screwed into the,

lower gage-cock fitting of a steam-boiler. The

top of the stand-pipe A is closed in by a capf ct, through which there is an air-passage stopped by a needle-valve c. The valve c has a passage d through its stem, and an opening e leads into this passage.

screwed out, so that the passage b is open, there is a free passage for air from inside the stand-pipe to the outer air.

On the top of the cap ci are two bearings ff, in which is hung a leverD. The leverD has a short arm g and a long arm h. The short arm is connected by a link-bolt g to a spur b on the coupling B. bolt g to the spur l) is by means of a screw and nuts n n, by means ofwvhich the effective length of the link-bolt may be adjusted. The

long arm 7i of the lever D is connected by a i link-support h to a bell-crank lever 7c, that is fulcrumed to a spur K, that extends from, At the the bottom of a whistlestandard s. top of the whistlestandard s is supported a steam-whistle T, and below the steanrwhistle T is a valve arranged to be held in a normally- The valve c when screwed in closes the passage d, and when` The connection of the closed position by a spring t, that surrounds its projecting stem. the valve engages an arm of the bell-crank lever 76, and the valve is opened by the pressure of the arm 7c against the stem.

The whistle-standard and the pipe leading into it are secured to a bracket R of the coupling B, and a steam-pipe p leads into it from Preferably it the steam-space in the boiler.

The projecting stem ofis arranged to be connected to the upper gagefrf The elbow C leads from the boiler at a lower.l

point than the steam-pipe p, and when the water in the boiler is lower than the opening in the steam-pipe p there is free access of ,steam through the pipe p as far as the valve at the top of the whistle-standard, because -of the steam-pressure in the boiler and because of the comparative coolness of the long and exposed standard A, said standard A being full of water, As soon, however, as the water falls to a level -with the entrance of the elbow C the water in the stand-pipe be-1 gins to run out, and the rod r causes it to run out rapidly, and the stand-pipe A fills with steam instead of water. The water in the stand-pipe A was comparatively cool, much cooler thanV the water in the boiler, because of its much greater exposure to radiation and because it was not circulating, but stagnant, and consequently the stand-pipe A increases in temperature rapidly as soon as the water runs out and the steam takes its place.

The increase of temperature increases the length of the stand-pipe, and its length in creases more rapidly than does the length of the link g or of the link 7L', and the lever D is turned on its fulcruin. rlhe link Yi/ pulls the bell-crank lever 7c, pushes in the valvestem, and opens the valve to the whistle, and the whistle at once signals the condition of the water. i

l have found experimentally that this alarm requires about two minutes time before the signal is sounded if the rod r is omitted and that it Will give the signal Within thirty seconds time after the steam begins to find entrance to the elbow C if the rod 1" is included.

What I claim is* In a 10W-Water alarm, in combination with a vertically-disposed stand-pipe, connections adapted to admit steam to the interior of the stand-pipe, a Whistle, Couplings connecting the Whistle to the pipe near the bottom thereof, a Valve controlling the passage of steam through the couplings, a lever arranged to l actuate the valve, a link joining the lever and the top of the stand-pipe, and a loose rod located in the stand-pipe and adapted to break the seal of the Watencolumn therein, substantially as described.

In testimony whereof I sign this specification in the presence of tWo Witnesses.

CLARENCE B. HODGES.

Witnesses:

CHARLES F. BURTON, ELLIOTT J. STODDARD. 

